1. Field of the Invention
With the explosion in technological innovation, there has been a coincident rise in the mechanization of society. By way of example, beginning with the simple reel type push mower, we now have riding mowers of all shapes and sizes, and sportsmen who once stalked the woods on foot, now ride in relative comfort on powerful all terrain vehicles.
ATVs are not only for fun. Rather, they work on farms and ranches, where they are favored because of their size and agility, over the more ponderous trucks which were traditionally the vehicle of primary reliance.
While the value of utility type trailers is obvious in a farm or ranch environment and for sport, such trailers have a variety of important uses in the lives of city dwellers and even those who live in apartments. Such trailers not only permit the hauling of ATVs and mowers, but fire wood, furniture, appliances, and landscaping materials, all material things encountered by people everywhere, are readily moved from the vendor who once, but no longer, delivers to their place of use, in utility trailers.
Since utility trailers of the type referenced here inherently have beds which repose on a set of wheels, they are necessarily off the ground, typically by at least the height of the axle. A tongue, or tow hitch, connects the frame of the trailer to a tow bar mounted on the towing vehicle, which may be a truck, sports utility vehicle, the family car, or even another ATV.
If the objects being towed are heavy, it is not always practical to lift them out of the trailer bed and, unless they are mobile, putting a ramp against the open end of the trailer bed will not always permit the safest way to unload the trailer. If the trailer is to be tipped about the axle to unload it, most such trailers must be disconnected from the tow hitch and, depending on the weight in the trailer, may be difficult, and even unsafe, to tip manually.
It is within this environment that the present invention has particular, although not exclusive, utility.
2. Overview of the Prior Art
The present invention is not the first utility trailer which is capable of being tipped to load and unload without disengaging it from the tow vehicle, but as a further reading of the Detailed Description will make evident, it is clearly the best.
As early as 1893, Butts and O'Marra perceived the value of a tiltable cart and patented their conception as U.S. Pat. No. 495,722. Their cart was used to dump material, e.g., ash from the cart off the end of a pier into a scow sitting below. The container was hinged to the frame of the cart and rotated about a hinge pin h when the horse backed the cart against a stop k, which is referred to as a string piece, to stop the wheels from further rotation.
In the 1962 patent to Schueller, U.S. Pat. No. 3,061,124, a boat trailer was equipped with a brake system which stopped the trailer wheels, and tilted the trailer bed when the tow vehicle proceeded to back up with the trailer wheels locked.
Several inventions have focused on limiting rearward movement of a vehicle, among them Hoffman U.S. Pat. No. 4,487,396 which involves chocks secured to the vehicle by a chain; Corti et al. U.S. Pat. No. 3,517,776, involving a complex mechanical mechanism for deploying chocks behind a truck, and a very early patent to Stuart, U.S. Pat. No. 828,633, which deployed a roller 15 as a brake behind a wagon.
Other inventors concentrated on mechanisms for selectively releasing the trailer bed from its transport position to permit rotation or tilting about the axle, among them, Gagnon U.S. Pat. No. 3,620,397; Carberry U.S. Pat. No. 4,494,797; Adams U.S. Pat. No. 4,872,728 and Kannady et al. U.S. Pat. No. 3,985,253.
Finally, Fortin, in his U.S. Pat. No. 4,711,499, combined many of the features of the prior art into his tipper trailer, except that rather than provide for stopping the wheels of the trailer as a means of creating a fulcrum for tilting the trailer bed, Fortin elects to use a sliding hinge which, hopefully, will permit the bed to be tilted at the desired point, on to blocks 14, which then stop further rotation of the wheels. Obviously, however, if there is no friction or other inhibitions, the wheels continue to rotate during rearward movement of the tow vehicle, the contents of the trailer may never be dumped, or if dumped, dumped in the wrong place.
The present invention, as will be quickly appreciated, combines the best features of the prior art in a unique and simple manner to achieve the objectives of the inventions, which are: